66731 has 4 divisors (see below), whose sum is σ = 76272. Its totient is φ = 57192.

The previous prime is 66721. The next prime is 66733. The reversal of 66731 is 13766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13766 = 2 ⋅6883.

It is a cyclic number.

It is not a de Polignac number, because 66731 - 2¹⁰ = 65707 is a prime.

It is a super-2 number, since 2×66731² = 8906052722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66697 and 66706.

It is not an unprimeable number, because it can be changed into a prime (66733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4760 + ... + 4773.

It is an arithmetic number, because the mean of its divisors is an integer number (19068).

2⁶⁶⁷³¹ is an apocalyptic number.

66731 is a deficient number, since it is larger than the sum of its proper divisors (9541).

66731 is an equidigital number, since it uses as much as digits as its factorization.

66731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9540.

The product of its digits is 756, while the sum is 23.

The square root of 66731 is about 258.3234406708. The cubic root of 66731 is about 40.5610520549.

It can be divided in two parts, 66 and 731, that added together give a palindrome (797).

The spelling of 66731 in words is "sixty-six thousand, seven hundred thirty-one".